1. Field of the Invention
The present invention is directed to a ceiling mounted fire detector assembly, and more particular to a mounting structure of a fire detector and its mount base assembly.
2. Description of the Prior Art
There have been proposed various types of ceiling mounted fire detectors which are detachably received into a mounted base installed to a ceiling surface. Such fire detectors are designed to send an electric alarm signal upon sensing a fire condition to a central control center through a signal line routed within the ceiling. For detachable mounting of the detector, it has been common to provide a pair of conductor prongs or the like rigid conductors on the detector for physically and electrically connect the detector to a corresponding pair of sockets which is provided on the mount base and is wired to the signal line through corresponding terminal screws. Such detector and mount base assembly has been known, for example, in Japanese Utility Model Publication (KOKAI) No. 58-94089. As seen in the prior art, the mount base in the form of a top-closed and bottom-open barrel is provided with the terminal screws on the interior surface of the barrel together with the sockets. Thus, the mount base is required to have an entrance hole for drawing the wires from the ceiling into the mount base for wiring connections with the terminal screws. Such entrance hole is normally formed centrally of the top wall of the mount base with the screw terminals arranged along the periphery of the entrance hole, as seen also in FIG. 14a of U.S.P. 4,017,733 which shows the like detector mounting structure. This structure imposes a severe limitation on reducing the size, particularly the diameter of the mount base because the wiring operation cannot be done easily without enough interior space afforded to the mount base. Otherwise, the wiring connections would be restricted within the limited interior space of the mount base and not be successful at such an elevated site on the ceiling. Due to this limitation, the prior art mount base is not permitted to have a reduced size, which in turn prohibits the total compact arrangement of the detector and mount base assembly, although the compact arrangement is highly demanded for making the detector less conspicuously and giving an improved aesthetically pleasing appearance.